This weekend’s Tasmanian state election is likely to be the last major election in 2025, barely halfway through the year, but that means the rest of this year will be redistribution season.
Two federal redistributions, in Queensland and Tasmania, are set to resume later this month when Parliament returns. Federal redistributions in South Australia and the ACT are also due soon. I will return to this topic in the next few weeks.
But the first redistribution of 2025 is the state redistribution of Queensland. The last redistribution took place prior to the 2017 election, and those boundaries have now been used for three state elections – no other state holds redistributions so infrequently.
Submissions from the public are now open. They will close on August 6. The Commission has not set out precise dates for the rest of the process, but they expect the draft boundaries to be published in early 2026.
For this post, I am going to run through the current population statistics and what that suggests for where seats may shift. There has also been a lot of comments about this redistribution in the comments sections of Queensland 2024 seat guides – you can bring the conversation to this post.
The Queensland Redistribution Commission (QRC) has published their own helpful discussion paper that covers a lot of the same data I will be analysing here. It’s worth examining because it also runs through the criteria the Commission will need to consider.
In short, each electorate needs to fall within 10% of the average enrolment (or ‘quota’) as of May 2025. There is also a ‘large district number’ which means that electorates with a land mass of over 100,000 square kilometres are granted ‘notional electors’ equivalent to 2% of the square kilometres in their electorate.
Right now four seats benefit from these notional electors, and they make up the equivalent of 70% of an electorate. Three of these four seats are currently below the average quota even with those notional electors, with one of them more than 10% under. All three of those seats are projecting to be more than 10% under the quota by 2032. So it is likely that the land mass of these seats will grow. There are two other seats with a land mass of 70-80,000 square kilometres, so it’s possible another seat could benefit from this rule.
This produces a conundrum when it comes to calculating how big a seat should be. The ‘average’ is based on a total population divided by 93 seats. But the actual number of electors that can contribute to a seat’s enrolment is actually about 93.7 seats, likely to go up slightly more. So the average seat should be drawn to be slightly above the average.
The QRC has also published enrolment projections for June 2032. These don’t appear to carry the same weight as the current figures. Unlike in a federal redistribution, there is no requirement that every seat fall withins a certain range, but a sensible Commission would aim to draw the faster-growing districts with a smaller starting population. Mapmakers are often conservative and thus do the opposite, making minimalistic changes which leave the faster-growing areas with above-average enrolments, but they shouldn’t.
Further down in this post, I’ve posted a map showing how much each seat varies from the 2025 and 2032 quotas. But I’ve also summed up the totals for each geographical region of Queensland.
Where one seat is under quota and its neighbour is over quota, it is relatively easy to adjust the border without making more dramatic changes. But when whole regions are well under- or over-quota, that is when more significant shifts are required, and potentially could see seats abolished or new seats created.
The first two columns of data reflect how much each seat varies from the actual quotas. Those quotas do not factor in the notional electors in the large districts, although those notional electors are included in those seats’ fulfillment of the quotas. That explains why these numbers don’t add up to zero. The last two columns adjust the quota upwards to include the existing notional electors, but can’t take account of new notional electors created if those seats are made larger. They do add up to zero.
The seats of urban south-east Queensland are significantly over quota. If it weren’t for the large district allowance, I’d argue that we’d see a seat in the regions abolished and one created in the city, but that may not happen. By 2032, the 61 seats in this area are expected to contain almost 63 quotas of electors.
When we look at a closer level, we can see that Ipswich and the Sunshine Coast have grown the fastest, with Ipswich expected to have a lot more growth over the next seven years.
The southern half of Brisbane is a third of a seat under quota. One difference between my analysis and that of the QRC is that they have split out the suburbs on the southern fringe and northern fringe of Brisbane, and merged Brisbane City into one area. There are a handful of seats in southern Brisbane that are well over quota: Logan is particularly over quota, as is the neighbouring Jordan (included in Ipswich) and Coomera (included in Gold Coast). But more established southern suburbs are consistently under quota. Those seats will likely have to expand south to absorb the surplus population in Coomera, Jordan and Logan.
The northern half of Brisbane has grown faster, and this growth is more even, although Murrumba has grown very fast. While the Gold Coast is due to grow, the region currently has about the right number of voters for its eleven seats. Gaven is well under-quota, but Coomera has enough surplus voters to top it up.
The seats of regional Queensland are consistently under quota. The seats around Cairns are about in line with the quota, but seats further south will likely need to grow. The three Townsville seats are about a quarter of a seat short of the third quota, and are surrounded by other seats falling under quota.
Submissions will close in early August, and I am planning to make a podcast to discuss those submissions along with the federal redistributions. There are plenty of directions the Commission can go in, but it seems likely that seats in the urban areas surrounding Brisbane will get smaller, potentially with a new seat created on the southern or northern edge of Brisbane, and the regional seats will have to grow. But there are a range of options for how the map can be drawn.
Finally this map shows how much each seat deviates from the average, both in 2025 and the projected numbers for 2032.
Thanks for the analysis Ben. The large district allowance really does complicate things, and it’s going to be interesting to see how Burdekin, Gregory and Traeger compete for limited space and electors.
Hope this is okay, but just wanted to make a quick plug for a redistribution tool that I shared on the Caloundra thread in case anyone in the community finds it useful.
https://github.com/auredistribution/qld-state-redistribution/blob/main/QLD-State-v0.1.zip
“To get going you’ll need to download the ZIP file and open the contained webpage. The file is around 50MB as it contains the shape data for all 12,545 SA1s in Queensland. Try not to open it while you have too many other tabs open as it takes up a fair bit of memory.
Once it’s up and running, I’m hoping everything is relatively self-explanatory, but if anything breaks or is unclear, just let me know. Any feedback is welcome.”
For some odd reason the QRC has decided to use red for the over quota seats and blue for the under quota seats.
Yes I noticed that. But I have stuck with my previous colour scheme.
Thanks heaps @Angas it looks very useful!